If you’re at high risk of getting HIV, taking preexposure prophylaxis therapy (PrEP) may be one of the best things you can do to protect your health.
PrEP is a preventive treatment for HIV. According to the U.S. Department of Health and Human Services, it can reduce the risk of contracting HIV from sex by up to 99%! It can also cut the risk of HIV from sharing drug injection equipment by at least 74%.
The Food and Drug Administration (FDA) has approved two types of oral PrEP (Truvada and Descovy), which are designed to be taken as a pill once a day. The FDA also recently approved a long-acting PrEP injection (Apretude), which people can take once every 2 months.
To get as much protection as possible from PrEP, it’s important to take it consistently.
But what if you want to pause PrEP or stop taking it altogether?
Here we share the facts about pausing (and restarting) this preventive treatment.
PrEP only works for as long as you take it. When you stop taking PrEP, the protection it provides against HIV quickly fades. You need to keep taking it for as long as you want that protection.
If you’ve tested negative for HIV, you may benefit from taking PrEP if:
- you’re having (or plan to have) anal or vaginal sex without a condom or other barrier
- you’re having (or plan to have) anal or vaginal sex with someone who has HIV
- you’ve received a diagnosis of a sexually transmitted infection in the past 6 months
- you inject drugs and have an injection partner with HIV or share injection equipment
- you have other risk factors that increase your chances of getting HIV
If your sex life or injection drug use changes, it may affect your risk of HIV and the potential benefits of PrEP.
You might decide to stop taking PrEP if you’re no longer at high risk of contracting HIV. Your doctor will likely advise you to keep taking PrEP for 7 to 28 days after your last sexual contact.
In most cases, stopping PrEP won’t cause any immediate side effects — but it may raise your risk of HIV, especially if you have risk factors that increase your chances of HIV exposure.
What are the potential benefits of stopping PrEP?
For one thing, you might find it more convenient not to take PrEP. It may save you money if you pay out of pocket for PrEP, although many health insurance plans cover the medication, and financial assistance programs are available.
Stopping PrEP may also relieve side effects, although the side effects are usually mild and often go away on their own over time.
What about the risks of stopping PrEP?
First and foremost, it means you no longer get the protective benefits against HIV. If you have active hepatitis B, stopping PrEP may also reactivate the infection.
It’s best to talk with your doctor before you stop taking PrEP. They can help you weigh the potential benefits and risks of stopping this medication.
What if you only occasionally have sex without condoms or with an HIV-positive partner? Do you need to take PrEP consistently, or can you wait until you’re planning to have sex?
Scientists have started to study an “on-demand,” or “event-driven,” approach to oral PrEP, known as the 2-1-1 schedule. In this approach, a person takes three doses of PrEP:
- Dose 1: 2 pills, 2–24 hours before sex
- Dose 2: 1 pill, 24 hours after dose 1
- Dose 3: 1 pill, 24 hours after dose 2
It’s important to note that the 2-1-1 approach has been studied only in men who have sex with men. Therefore, the recommendations apply only to that population. Scientists have found that this method can help reduce the risk of HIV in men who have sex with men without a condom.
In a 2015 study, those who took 2-1-1 PrEP were 86% less likely to develop HIV than those who took no PrEP at all. More research is needed to learn whether 2-1-1 PrEP works well for people of any gender, sex, or sexual orientation and for people who inject drugs.
You might find the 2-1-1 schedule appealing, but it’s not the right fit for everyone. If you have active hepatitis B, following the 2-1-1 schedule may reactivate the infection. Some people also find it tricky to follow the 2-1-1 schedule. You need to know when you’re going to have sex and remember to take all three doses.
The FDA hasn’t yet approved 2-1-1 PrEP, and the Centers for Disease Control and Prevention (CDC) doesn’t recommend it either. But the World Health Organization offers recommendations for event-driven PrEP use, and the International AIDS Society has recommended it off-label for men who have sex with men.
Even so, some doctors may be willing to prescribe 2-1-1 PrEP off-label.
You can talk with your doctor to learn more about the potential benefits and risks of 2-1-1 PrEP.
Off-label use refers to prescribing medication for use in a way that the FDA hasn’t approved.
When you stop taking PrEP, the amount of medication in your blood drops until there’s none left. The protection it provides against HIV wears off too. This makes it easier for HIV to multiply in your body if you’re exposed to the virus, raising your risk of contracting HIV.
Depending on how many doses of PrEP you’ve taken, the medication may take a few days or longer to leave your body. You may have partial but not full protection against HIV for a few days after stopping PrEP.
For most people, there are no known side effects or withdrawal symptoms from stopping PrEP.
But if you have chronic hepatitis B, stopping PrEP may cause the hepatitis virus to become more active in your body.
Why is that? Because one of the drugs in PrEP stops both HIV and hepatitis B from multiplying. Your doctor can help you understand and manage the risks.
Yes! Unless you’ve developed serious side effects from PrEP (which are rare), you can start taking it again after pausing or stopping.
It’s important to talk with your doctor before you restart PrEP. They will order an HIV test to make sure you’re still HIV-negative. PrEP is appropriate only for people without HIV.
If you’re taking oral PrEP, the CDC encourages you to take it every day for optimal protection against HIV. That means no missed or skipped doses.
But we’re all human. Mistakes happen — and missed doses aren’t uncommon.
If you’ve been taking oral PrEP every day and you miss a single dose, you probably have enough medication built up in your bloodstream to protect against HIV. The following tips may help:
- If you remember the missed dose before your next dose is due, the CDC recommends taking it right away.
- If you don’t remember it until your next dose is due, skip the missed dose and continue your regular schedule.
- Don’t take a double dose of PrEP.
If you’ve been following the 2-1-1 schedule, you will have less medication built up in your bloodstream. Keep the following in mind:
- Missing any one of the three doses could undermine the protection that the medication provides.
- If you miss any of the doses and think you may have been exposed to HIV, contact your doctor or an urgent care center right away.
- Your doctor may recommend postexposure prophylaxis (PEP), which is another form of HIV prevention.
The more doses of PrEP you miss, the less protection it will provide against HIV.
If you regularly miss doses of oral PrEP, let your doctor know. They may share strategies to help you remember your doses.
In some cases, they may also encourage you to consider injectable PrEP. You need to get an injection of this medication only once every 2 months to protect against HIV.
Taking PrEP can greatly reduce your risk of getting HIV — but only as long as you keep taking it.
If you stop taking PrEP, the protective benefits will quickly wear off.
It’s best to talk with your doctor before you stop taking PrEP. They can help you understand the potential benefits and risks, including the possible effects on your risk of contracting HIV.